1. Field of the Invention
The present invention relates to a direct driving apparatus for an electric treadmill, and more particularly, to a apparatus which applies the brushless motor to enable a turning wheel to directly drive the roller of the running belt.
2. Description of the Prior Art
The treadmill is widely regarded as a practical indoor exercise apparatus with the best exercise effect. The electric treadmill has the speed-adjusting merit in accordance with different using requirements. The primary driving apparatus of a conventional electric treadmill, as shown in FIG. 1 and 2, includes a motor 12 with a reduction gear box. A belt transmission wheel or a toothed wheel 14 at the side of the roller 15 is driven by means of a belt or a drive chain 13 so that the roller 15 brings the running belt 16 in motion. The greatest disadvantage of the above-mentioned device is that the transmission of the belt or the chain 13 causes noise and vibration. Moreover, the power output axle 12 of the motor 12 rotates rapidly and its torsion is small so that the roller 15 can't be directly driven by the output axle. It's required that the speed of the output axle has to be reduced by means of the reduction gear and the gear 14 to increase the torsion for driving the roller 15 in motion. However, it can't be used as non-motorized treadmill at power failure or without power supply because the running belt 16 can't bring the roller 15 in motion. Additionally, the transmission members like belt or chain cause abrasion problem so that its life is shortened.